Gold nanorod-photosensitizer complex obtained by layer-by-layer method for photodynamic/photothermal therapy in vitro.

Gold nanorod (GNR)-photosensitizer (PS) complex was prepared using anionic PS (sodium salt of purpurin-18) and cationic poly(allylamine hydrochloride) by layer-by-layer method, and was characterized by transmission electron microscopy, UV-vis spectroscopy, and zeta potential. The GNR-PS complex is a promising agent for synergistic (photothermal and photodynamic) therapy (PTT/PDT), in which PTT generates heat as well as operates the PS release which maximize the following PDT activity. The combined dual therapy, PTT followed by PDT, exhibits a significantly higher photocytotoxicity result based on synergistic effect of hyperthermia from PTT as well as singlet oxygen photogeneration from PDT.